Self-contained breathing apparatus



April 7, 1925. 1,532,654

A. B. DRAGER SELF CONTAINED BREATHING APPARATUS Filed June 9, 1921 Patented Apr. '7, 1925.

. uairsn I stares ear ALEXANDER Bananas!) rink-lean, or LUBEOK, GERMANY.

SELF-CONTAINED BREATHING APPARATUS.

Application filed June 3, 1921. Serial No. 476,237.

To all 107mm it may concern:

lie it known that I, ALEXANDER BERN- rmno Dizlienn, a citizen ot Germany residing at Lubeclr, Germany, have invented certain new and useful Improvements in Self- Contained Breathing Apparatus, of which the following is a specification.

This invention relates to self-contained breathing apparatus for use in noxious gases and the like, which is principally composed of a cartridge having an air'purifying charge adapted for the absorption of carbonic acid from the exhaled air, breat-l ing pipes controlled by breathing valves, an

oxygen container and a breathing bag,

which parts are so put together in the well known way vthat the exhaled air passes through or contacts the purifying charge and is breathed in again as purified air with or without revivitying oxygen, while any excess of the purified or revirilied air passes into the breathing bag.

Before such an apparatus is put into use, the breathing bag, and the lungs also as much as possible must be emptied 0t ordinary respirable air, up to our fifths of which, as is well known, consists oi nitrogen. The reason for this'is that it too much nitrogen remains in the air within the apparatus,-the person wearing the same is const-antly subjected to a lack of oxygen,,be cause, as soon as the oxygen in the breathing bag is used up he will then receive only nitrogen into his lungs. This deficient sup-.

ply of oxygen to the blood will be manifested by the wearer ot the apparatus soon becoming insensible.

Contamination of the air in the apparatus can also be caused by traces of poisonous gases getting into the apparatus from outside, when during inhalation a certain decrease or reduction of pressure is produced and the apparatus is not perfectly air tight all over in all its several parts. The traces of such inhaled poisonous gases may accumulate during the course of the action of breathing to a dangerous extent, especially since the poisonous gases entering the apparatus invariably remain therein. It must be remembered that it is possible for such a danger to occur in every self-contained breathing apparatus because a certain increase of pressure is produced on exhalation and a certain reduction of pressure on inhalation, as otherwise air takes place.

no movement of the These disadvantages can be obviated or at. any rate reduced to a minimum, if the breathing bag be so constructed that it has a tendency and the power to setitself in a flat extended or deflated position and thereby automatically empty itself. In the breathing bags hitherto usually employed and not provided with any means of deflation, such automatic setting of the bag into the flat position is not possible. According to this invention the object aimed at is attained by providing the breathing bag with means combined with the bag in a manner to automatically deflate the same at the proper time and thereby expel its contents into the apparatus. The means in question may comprise springs carried by the bag and exerting a force whereby its deflation and the expulsion of its contents is brought about. In the illustrated example the bag is provided with suitably formed and arranged extending springs, which tend to set or spread the breathing bag in a flat position or hold it flat. Such a breatl ing bag will be entirely emptied of air by its own action at the beginning of the action of inhaling. On the other hand such a breathing bag provided with means for its automatic deflation, will, owing to its being still more or less inflated during the operation or breathing, immediately force air to support respiration into the apparatus when the reduction of pressure occurs due to inhalation and thereby prevent or obviate any injurious suctional action of the reduced pressure on any leaking places in the apparatus. In other words a pressure is applied to the contents of the breathing bag which is always above normal pressure and the fresh breathing gas is driven by this supernormal pressure into the lungs during the inhalation period and during the exhalation period the gas is expelled from the lungs against the superno-rma-l pressure.

The use of a breathing bag provided with automatic deflating means may under some circumstances render exhalation somewhat 'ditlicult. This disadvantage is however so small in comparison with the advantages secured that it can well afford to be ignored. In the drawing is shown diagrammatically a constructional example of a breathingbag constructed according to this invention applied by way of example to a breathing apparatus constructed to be carried on the back and to which oxygen is continuonsly supplied at a fixed pressure and in nieasrred quantities during the action of ot the ret'erence letters on the will suffice here.

' d by a *alve w ring car ridge or absorber 2. i e in i end of tae absorber p is connected by a pipe 7), an inhalation valve n and an inhalation pipe 6 to the monthpiece in. To the breathing; pipe Z) is connected on the one hand a breathing bag 5 by means of a connecting anion (Z and on the other hand n. =en h ttle f by means of a pipe it in which a pressnre reducing valve 1 'nserted.

In the interior of r which is approxirnatel} rectal gnlar in shape and connected to the air pipe Z), are placed two extending spri n and 0. Each spring consists of a wire coiled into the form of a loop with tree arms which spring apart. The springs are inserted cross-wise in the hay; and in sncl a way that the arms of the spring a bear interior-hr against the corners 1. and 55 of the bag" 5 and the arms of the spring; 0 intcriorly against the corn PIS 2 and thercot. B this arrangement the breathbaa is not. only stretched tightly in the 1 of its two diagi'n -als, but also in the oireei four side edges or in other words is stretchc-e in two directions transverse to each other so that both its at on each other or have a tendt position by a force e snriags selected, when and therelw cor espond l ti c breathing bag .9,

inflation ceases ing; amount of ar LO support respiration is eed at certain pressure into the air passage of the apparatn, in order to prevent a; y undesirable snetio'nal action due to reduced pressure atany points of the apparains which may not be quite air-tight.

The arrangement of the springs selected or their equivalents ensures at the same time he breathing bag: being sufficiently 1n0vah e in all directions, so that the freedom OI. nioveinent ot' the person carrying or wearing the apparatus is not in an "ay interfered with.

1 n'i th the a;

pellin o the ap l e ntained breatlri' tns, the cenihination of n rice an oxygen cont connected with la-eathi 41' valves Ci 1- pipes a breathing sain. pipes and a ra ,1

air., and sprinc e I a torce where n' tical Cetlated to T tnsl the conihinati-fn of a; rice. an oxygen coat connected with said device ln'eathinp; valves centrollii pipes, a breathing;- hagr ron'rznnnicati said iipes and arranged to receirc rev vi rd air, and sprinp's carried hr sai l i t n.;l ranged tospre: l the sanie t S5 expel its contents into the a s.

" in a srl'i -conta d bro appara- 14in the combination ot' an air-p Yicix an or container. bro connected w:

rinrz depipes th said dm'ice an; hrcathinp; ralres controllint; said l pipes an appror-zimatch rectn on ing; bag chnnnnnicating with ind springs located within said ,i caringin eriorlv against the eorneis thereoi whcrehv said ba is retched in two directions iiRHSWTSL lO e fia'ed to er-rnel its contents a resilient nicnihcr carried ti niaintaininga snperpressare in the breath ling hag during the inhalation and exhrlalion periods.

7. In an apparatus tor providing breath- 111g gas for the lungs, a hreathinr hair a snpplr source tor supplying: gas nto the hag. and. means carried nf the maintaining the gas supply in the hag: at a 115 3. in an aoparatns tn tor e lanes a c-rnn'ce Jlillinfl' bag: "tor inaxntmnii ply in the bag; at a superpre,

ALEXANDER BEazill-iARD 

